Re: [PATCH v5 4/4] rtc: ds1307: add frequency_test_enable sysfs attribute to check tick on m41txx

[Giulio Benetti]

Hi,

Il 16/05/2018 22:22, Andy Shevchenko ha scritto:
> On Wed, May 16, 2018 at 1:32 PM, Giulio Benetti
> <giulio.benetti@xxxxxxxxxxxxxxxx> wrote:
> > On m41txx you can enable open-drain OUT pin to check if offset is ok.
> > Enabling OUT pin with frequency_test_enable attribute, OUT pin will tick
> > 512 times faster than 1s tick base.
> >
> > Enable or Disable FT bit on CONTROL register if freq_test is 1 or 0.
> >
> > Signed-off-by: Giulio Benetti <giulio.benetti@xxxxxxxxxxxxxxxx>
>
> > +static ssize_t frequency_test_enable_store(struct device *dev,
> > +                                          struct device_attribute *attr,
> > +                                          const char *buf, size_t count)
> > +{
> > +       struct ds1307 *ds1307 = dev_get_drvdata(dev);
> > +       unsigned long freq_test = 0;
> > +       int retval;
> > +
> > +       retval = kstrtoul(buf, 10, &freq_test);
> > +       if ((retval < 0) || (retval > 1)) {
>
> kstrtobool() then?

Yes, you're right.

> > +               dev_err(dev, "Failed to store RTC Frequency Test attribute\n");
>
> > +               return -EINVAL;
>
> ...and do not shadow actual error code.

Ok

> > +       }
> > +
> > +       regmap_update_bits(ds1307->regmap, M41TXX_REG_CONTROL, M41TXX_BIT_FT,
> > +                          freq_test ? M41TXX_BIT_FT : 0);
> > +
>
> > +       return retval ? retval : count;
>
> Does the condition make any sense?

You're right, not at all.
I changed it into:
"return count;"

> > +}
>
> > +static ssize_t frequency_test_enable_show(struct device *dev,
> > +                                         struct device_attribute *attr,
> > +                                         char *buf)
> > +{
>
> > +       int freq_test_en = 0;
>
> > +       if (ctrl_reg & M41TXX_BIT_FT)
> > +               freq_test_en = true;
> > +       else
> > +               freq_test_en = false;
> > +
> > +       return sprintf(buf, "%d\n", freq_test_en);
>
> So, is it boolean or integer? This code makes it confusing a lot.

It is a boolean, so now I've updated with this:

if (ctrl_reg & M41TXX_BIT_FT)
	return scnprintf(buf, PAGE_SIZE, "on\n");
else
	return scnprintf(buf, PAGE_SIZE, "off\n");

> > +}

Thank you very much for review

Giulio Benetti